Directions

In a medium saucepan, combine bittersweet chocolate, butter, and peanut butter. Cook and stir over low heat until melted. Cool. Preheat oven to 350 degrees F. Line an 8x8x2-inch baking pan with foil, extending the foil over edges of pan. Grease foil; set pan aside.

Stir brown sugar into cooled chocolate mixture. Add eggs, one at a time, beating with a wooden spoon after each addition. Stir in vanilla. In a small bowl, stir together flour, baking soda, and salt. Add flour mixture to chocolate mixture; stir just until combined. Stir in 1 cup chopped peanut butter cups. Spread batter evenly in the prepared baking pan.

Bake in the preheated oven about 30 minutes or until set. Cool in pan on a wire rack. Spread Nutty Frosting over brownies. Using the edges of the foil, lift brownies out of pan. Cut into bars. If desired, sprinkle with additional chopped peanut butter cups. Makes 24 brownies.

From the Test Kitchen

Layer brownies between sheets of waxed paper in an airtight container; cover. Store in the refrigerator for up to 3 days or freeze for up to 3 months.